Degradation Of Norfloxacin Research Articles

Photocatalytic degradation of norfloxacin antibiotics on ZnxCd(1-x)S/g-C3N4 composites in water.

g-C3N4/ZnxCd(1-x)S composites were synthesized by a simple hydrothermal method. The composites were characterized by X-ray diffraction, UV-vis diffuse reflectance spectroscopy, infrared spectroscopy, and electron micro-projective microscopy. According to the performance of ZnxCd(1-x)S for the photocatalytic degradation of norfloxacin under visible light in water, the best stoichiometric number of x was 0.5. The best photolytic norfloxacin degradation rate of g-C3N4/ZnxCd(1-x)S composites was 89.8%, which was obtained when the dosage ratio of g-C3N4 to ZnxCd(1-x)S was 1:1. The experiment was conducted to investigate the effect of pH on the catalyst to obtain the optimal NORF degradation environment pH in the range of 7 ± 0.3; by simulating the anions that may be contained in the actual environmental water, the results showed that the catalyst has a certain effect on the degradation of NORF when the water contains NO3-, Cl- and HCO3-. In addition, this study also obtained that the main active substances produced by the catalyst during degradation were electron-hole pairs by adding different trapping agents in the NORF removal experiments; and the catalyst was able to achieve a degradation rate of 86.1% after four cycles of the experiments, which proved that it had good stability.

Bimetallic iron-copper nanozyme for determination and degradation of norfloxacin in foods

Iron-copper nanozymes (Fe-Cu NZs) with good peroxidase activity were prepared through hydrothermal method by using copper nitrate as copper source, iron acetate as iron source and 2, 5-dihydroxyterephthalic acid as organic ligand. Upon oxidation of the colourless TMB to light blue products by Fe-Cu NZs, the addition of Norfloxacin (NOR) resulted in a colour change to dark blue. The absorbance of the system correlated linearly with NOR concentration in the range of 3.3 μM to 66 μM, and the detection limit (LOD) was 0.386 μM. A rapid colourimetric assay for the determination of NOR in food matrices was developed, with a detection time of only one minute. Additionally, the assay facilitated the simultaneous catalytic degradation of NOR via Fe-Cu NZs. The primary degradation mechanism of NOR was identified as the transformation of the quinolone ring and the cleavage of the C9 = C10 double bond, which was substantiated by high-performance liquid chromatography (HPLC).

Study on the degradation and metabolic mechanism of four quinolone antibiotics by mixed strains

Quinolone antibiotics are a common class of antibiotics in the environment and have received considerable attention. In this study, three groups of mixed degradation strains targeting mixed quinolone antibiotics, norfloxacin (NOR), and enrofloxacin (ENR) were selected through screening, enrichment, and microbial diversity detection experiments. The strains screened in this study are divided into two categories through degradation efficiency experiments, community composition detection and functional enrichment analysis. In groups mix and ENR, the resistant bacteria are the main microorganisms and the degrading bacteria are the secondary ones, while in group NOR, the strains with degradation effects are the main ones, and the strains with resistance effects are the secondary ones. What’s more, that carbon sources have little effect on the community composition of the quinolone antibiotic degrading and tolerant bacteria, the difference between groups is mainly controlled by the type of antibiotics. On this basis, we found the key to NOR degradation is the cleavage of carbon nitrogen bonds on the piperazine ring, followed by oxygenation and deethylation. Preliminary studies have confirmed that the optimal degradation conditions for NOR degrading strains, and also found that environmental factors did not significantly affect the degradation efficiency of the Mix and NOR degrading strains, which indicating that the mixed bacteria can degrade NOR in different real environments effectively such as tap water, seawater, river water, and lake water. This manuscript is the first report on a mixed strain of quinolone antibiotic microbial degradation, and it is also the study with the highest NOR degradation efficiency among known reports. It has great research value for the co-metabolism and biodegradation of quinolone antibiotics in the environment.

Simultaneous removal of lead, cadmium, and norfloxacin by Calcite/PMS system: Performance and mechanisms

This work investigated the performance and mechanisms of calcite activating peroxymonosulfate (PMS) for the simultaneous elimination of lead (Pb(II)), cadmium (Cd(II)), and norfloxacin (NOR). At an initial pH = 7, 1.0 g/L calcite, and 0.5 mM PMS, the removal of Pb(II), Cd(II), and NOR was 97.5%, 96.0%, and 98.1%, respectively. The results of EPR, quenching, and chemical probe quantification experiments revealed that singlet oxygen (1O2) derived from calcite activating PMS dominated NOR degradation. Meanwhile, surface complexation and carbonate precipitation were identified as the main mechanisms in the removal of Pb(II) and Cd(II) by ATR-FTIR and different ionic strength experiments, respectively. Kinetic analysis and XPS results indicated that the solid phase Pb(IV) generated through surface complexed Pb(II) oxidized by PMS facilitated the NOR degradation. The NOR degradation pathway along with biological toxicity assessment was also presented through HPLC-MS and ECOSAR software. This study provides the prospects of using natural carbonate minerals to activate PMS for treating the combined contamination of antibiotics and heavy metal ions, and also provides a new understanding of the removal of organic substances in the presence of heavy metal ions.

Recovery hydrotalcite from neutralization sludge of acid mine drainage with high manganese for degradation of norfloxacin with activated peroxymonosulfate

Acid mine drainage is rich in metals (including transition metals), so the neutralization treatment based on AMD for in situ regulation will ultimately result in sludge with potential catalytic effects. In this study, we reported a catalyst (MC-LDHs) that differed from traditional catalysts in that it was derived from AMD neutralized sludge containing high concentrations of Mn, which was a typical industrial waste. The catalytic performance of activated PMS for the removal of norfloxacin (NOR, a typical antibiotic) was evaluated under different operating conditions. The contribution of active species in the reaction system was evaluated through quenching experiments, and the types of free radicals were further determined through electron spin resonance experiments. In addition, density functional theory was used to simulate the electron transfer and vulnerable sites of NOR in the adsorption of PMS by MC-LDHs. Subsequently, the degradation pathway of NOR was inferred based on DFT results, and the toxicity changes of intermediate products were predicted. This study has reduced the cost of catalysts and simplified the preparation process of doped catalysts, thus providing a new strategy for catalyst preparation, which is of great significance for the promotion and application of advanced oxidation process.

Self-assembled oxygen vacancies modified hierarchical hollow tubular Bi2WO6/In2O3 Z-scheme heterojunction for optimized photocatalytic degradation of norfloxacin

The elaborate design of efficient strategy to facilitate interfacial and spatial charge separation is a prospective strategy for the enhancement of photodegradation activity. Herein, the oxygen vacancies modified hierarchical hollow tubular Bi2WO6/In2O3 heterostructure was synthesized via an in situ self-assembly method using MIL-68(In) as precursors and structural component, which can modulate charge redistribution for effective photocatalytic norfloxacin degradation (90.8%) in 50 min. The XRD, ESR, HRTEM, and XPS characterizations significantly prove the existence of oxygen vacancies and the successful construction of Bi2WO6/In2O3 heterojunction. Furthermore, the optimal BWO/In2O3-25 catalyst exhibits excellent degradation efficiency of NOR in practical water matrices and superior decomposition performances of tetracycline (82.1%), ciprofloxacin (82.4%), levofloxacin (88.2%), methyl orange (86.3%), methylene blue (93.2%), and rhodamine B (94.7%). Importantly, the toxicity of NOR can be ignored after the degradation. Capture experiments and DFT calculations collaboratively demonstrate the Z-scheme charge migration mechanism. This study presents a novel opinion for rational developing oxygen vacancies modified Z-scheme heterojunction with unique spatial and interfacial charge flow steering via a facile strategy.

Extrinsic defects-rich biochar for efficient peroxydisulfate activation: Electronic structure modulation and disparate nonradical mechanisms

Doping nitrogen atoms into carbon materials will produce abundant extrinsic defects, which can significantly improve the catalytic activity toward water remediation. However, there is still a lack of systematic research on which extrinsic defect is the real active site and how extrinsic defects enhance the catalytic activity of carbon materials. In this work, the sludge derived biochar with different configuration of extrinsic defects (pyrrolic-N, pyridinic-N, and graphitic-N.) were successfully synthesized by controlling nitrogen doping amount. The adsorption experiments showed that the biochar with rich graphitic-N significantly enhanced the adsorption ability of peroxydisulfate (PDS), which further led to the excellent catalytic activity toward norfloxacin (NOR) degradation, with 91 % removal efficiency within 90 min. The pseudo-first-order degradation rate constant (Kobs) was strongly positively correlated with the content of graphitic-N. Electron paramagnetic resonance (EPR) analysis and quenching experiments revealed that metastable reactive species (PDS*) were the dominated reactive species in NBC/PDS system. Besides, density functional theory (DFT) calculations demonstrated that the existence of graphitic-N most effectively improved the charge transfer among biochar, PDS and NOR compared to pyrrolic-N and pyridinic-N. Electrochemical characterization and Raman results further identified that graphitic-N heightened the direct electron transfer rate due to the formation of PDS*. The Fukui function predicted the reactive sites of NOR. All of these led to the high NOR removal efficiency. This study provided new insights for the design of non-metallic biochar catalysts with rich extrinsic defects for effectively activating PDS to degrade fluoroquinolone antibiotics.

Ball-milled pyrite@biochar induced percarbonate activation for sustainable degradation of antibiotic norfloxacin at inherent pH environment

Advanced oxidation processes utilizing percarbonate (SPC) have garnered considerable interest in the realm of water purification, but the all-encompassing constraint on pH conditions largely hindered its environmental applications. Here, a combination process of ball-milled pyrite@biochar and SPC was constructed to accelerate the degradation of norfloxacin (NOR) at an inherent pH environment. Results showed that the ball-milled pyrite@biochar + SPC system accomplished almost complete removal of NOR within 60 min, demonstrated excellent pH resilience ranging from pH 3.0 to 10.0, and manifested over 90 % NOR removal in cycle operation. The main mechanism of NOR removal encompassed both adsorption and oxidation processes. The NOR initially adhered to the ball-milled pyrite@biochar interface. Then, the interaction of the ball-milled pyrite@biochar and SPC yielded a multitude of reactive oxygen species (ROS), such as •OH, O2•−, and 1O2, along with electron complexes. The enhanced performance of SPC activated by the ball-milled pyrite@biochar could essentially be attributed to the greater Fe3+/Fe2+ circulation and better electron utilization efficiency through the existence of sulfur species and oxygen-containing functional groups. Accordingly, the regenerated Fe2+ was able to rapidly activate SPC for the production of ROS and electron complexes. Moreover, three possible NOR degradation pathways were put forward. It was illustrated that the application of the ball-milled pyrite@biochar + SPC could effectively reduce the ecotoxicity of NOR in wastewater. Overall, this study established a solid foundation for the implementation of ball-milled pyrite@biochar + SPC system in efficient water purification process.

Urea and ammonium fluoride di-nitrogen and Cu & Fe bi-metal co-doped carbon felt as cathode for electro-Fenton degradation of norfloxacin: 1O2-dominated oxidation pathway

Dual nitrogen source co-doped carbon with copper and iron induces 1O2 degradation of norfloxacin.

Effect of copper doping on the photocatalytic performance of Ni2O3@PC membrane composites in norfloxacin degradation.

In this study, copper (Cu) and nickel oxide (Ni2O3) microtubes (MTs) were synthesized using an electroless template deposition technique within porous polycarbonate (PC) track-etched membranes (TeMs) to obtain Cu@PC and Ni2O3@PC composite membranes, respectively. The pristine PC TeMs featured nanochannels with a pore density of 4 × 107 pores per cm2 and an average pore diameter of 400 ± 13 nm. The synthesis of a mixed composite, combining Cu and Ni2O3 within the PC matrix, was achieved through a two-step deposition process using a Ni2O3@PC template. An analysis of the resultant composite structure (Cu/Ni2O3@PC) confirmed the existence of CuNi (97.3%) and CuO (2.7%) crystalline phases. The synthesized catalysts were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) analysis, and atomic force microscopy (AFM). In photodegradation assessments, the Cu/Ni2O3@PC mixed composite demonstrated higher photocatalytic activity, achieving a substantial 59% degradation of norfloxacin (NOR) under UV light irradiation. This performance surpassed that of both Ni2O3@PC and Cu@PC composites. The optimal pH for maximum NOR removal from the aqueous solution was determined to be pH 5, with a reaction time of 180 min. The degradation of NOR in the presence of these composites adhered to the Langmuir-Hinshelwood mechanism and a pseudo-first order kinetic model. The reusability of the catalysts was also investigated for 10 consecutive runs, without any activation or regeneration treatments. The Cu@PC membrane catalyst demonstrated a marked decline in degradation efficiency after the 2nd test cycle, ultimately catalyzing only 10% of NOR after the 10th cycle. In contrast, the Ni2O3@PC based catalyst demonstrated a more stable NOR degradation efficiency throughout all 10 runs, with 27% NOR removal observed during the final test. Remarkably, the catalytic performance of the Cu/Ni2O3@PC mixed composite remained highly active even after being recycled 4 times. The degradation efficiency exhibited a gradual reduction, with a 17% decrease after the 6th run and a cumulative 35% removal of NOR achieved by the 10th cycle. Overall, the findings indicate that Cu/Ni2O3@PC mixed composite membranes may represent an advancement in the quest to mitigate the adverse effects of antibiotic pollution in aquatic environments and hold significant promise for sustainable water treatment practices.

The composite metal cluster catalyst Ni–MCM enhances the non-radical pathway for efficient catalytic degradation of norfloxacin

Norfloxacin (NOR) is a synthetic antibacterial agent that is extensively applied in the management of various infectious conditions.

High-efficiency degradation of norfloxacin by Co–N co-doped biochar synergistically activated peroxymonosulfate: experiments and DFT calculations

Co–N co-doped biochar synergistically activated PMS for high-efficiency degradation of NOR. Graphitic N and pyridinic N co-promoted the non-radical mechanisms, including direct electron transfer, 1O2, and high-valent cobalt-oxo (CoIVO) species.

Systematic investigation of peracetic acid activation by UV/ferric(III) hydrate oxide for efficient degradation of norfloxacin: Mechanisms and applications

Peracetic acid (PAA) based advanced oxidation process (AOP) has garnered significant interest in degrading fluoroquinolone antibiotics (FQs), but most studies ignored the secondary contamination caused by the released F−. In this study, ultraviolet (UV) coupled with hydrated Fe(III) oxide (HFO) was employed to enhance PAA activation for advanced removal of norfloxacin (NX). The UV/HFO/PAA system employing reactive oxygen species (ROS) dramatically improved the NX removal efficiency, achieving complete removal within 30 min at neutral pH. The UV/HFO/PAA system suffered slight interference from existing substrates but was hampered by carbonates and humic acid (HA). NX removal efficiency still retained at 96.7 % after five cycles of HFO adsorption-desorption. PAA was the main source of ROS in the UV/HFO/PAA process rather than H2O2. ROS mainly destroyed NX to form F− and other intermediates, and then F− was in situ locked by HFO adsorption. This study will facilitate further research of the UV/HFO/PAA system as a potential strategy for degrading FQs.

Construction of ZnCdS/TiO2 Z-Scheme heterostructure with excellent photocatalytic performance for degradation of norfloxacin

In this study, the binary heterojunction photocatalyst of ZnCdS modified TiO2 nanorod arrays was successfully prepared by hydrothermal method and successive ionic layer adsorption and reaction (SILAR). The ZCST-12 showed high removal efficiency (93.1%) of norfloxacin (NOR) within 90 min. The rate constant Kα was 0.0278 min−1 and the transient photocurrent density of ZCST-12 was up to 63 μA/cm2, which were 3.08 and 3.7 times higher than that of unmodified TiO2. The synergistic effect of ZnCdS and TiO2 broadens the range of light absorption, makes the absorption edge red shift, and greatly improves the light absorption and utilization ability of the material. The ZnCdS/TiO2 Z-scheme heterojunction greatly promotes the separation of electrons and holes and accelerates the carriers transport, preserves the strong redox ability of spatially separated holes and electrons, and effectively improves the photocatalytic performance. This study provides a simple method for preparing ZnCdS/TiO2 heterojunction photocatalyst.

Enhancement of norfloxacin degradation by citrate in S-nZVI@Ps system: Chelation and FeS layer

The degradation of organic pollution by sulfur-modified nano zero-valent iron(S-nZVI) combined with advanced oxidation systems has been extensively studied. However, the low utilization of nZVI and low reactive oxygen species (ROS) yield in the system have limited its wide application. Herein, a natural organic acid commonly found in citrus fruits, citric acid (CA), was combined with the conventional S-nZVI@Ps system to enhance the degradation of norfloxacin (NOR). The addition of CA increased the NOR removal by about 31% compared with the conventional S-nZVI@Ps system under the same experimental conditions. Among them, the enhanced effect of CA is mainly reflected in its ability to promote the release of Fe2+ and accelerate the cycling of Fe2+ and Fe3+ to further improve the utilization of nZVI and the generation of ROS; it also promotes the dissolution of the active substance (FeS) on the surface of S-nZVI to further improve the degradation rate of NOR. More importantly, the chelate of CA and Fe2+ (CA-Fe2+) had higher reactivity than alone Fe2+. Free radical quenching and electron spin resonance (ESR) experiments indicated that the main ROS for the degradation of NOR in the CA/S-nZVI@Ps system were SO4•- and OH•. CA-bound sulfur-modifying effects on NOR degradation was systematically investigated, and the degradation mechanism of NOR in CA/S-nZVI@Ps system was explored by various techniques. Additionally, the effect of common anions in water matrix on the degradation of NOR in CA/S-nZVI@Ps system and its degradation of various pollutants were also studied. This study provides a new perspective to enhance the degradation of pollutants by S-nZVI combined with advanced oxidation system, which can help to solve the application boundary problem of S-nZVI.

ZnO-Ti3C2TX composites supported on polyacrylic acid/chitosan hydrogels as high-efficiency and recyclable photocatalysts for norfloxacin degradation

Photocatalysts immobilized on hydrogels is a win-win mode, which not only improves photocatalysis but also successfully prevents catalyst loss, making it easy to separate and reuse during catalytic process. Here, ZnO-Ti3C2TX photocatalysts are loaded into the chitosan/polyacrylic acid hydrogel networks, realizing the efficiently photocatalytic degradation of norfloxacin. The chitosan-based composite hydrogel features rich functional groups and a dense pore structure, which is beneficial to antibiotic enrichment and photocatalytic degradation. The effects of different catalyst ratios, dosage, initial concentrations and pH on the degradation efficiency are investigated. The norfloxacin degradation rate constant is 0.012 min−1 and its degradation efficiency reaches up to 90 % after 240 min. Importantly, the photocatalytic composite hydrogel still retains 85 % degradation efficiency after 6 cycles. Moreover, e− plays a significant role in the degradation process. This work converts the traditional powder photocatalysts into bulk photocatalysts (photocatalytic hydrogels) to accomplish efficient degradation and rapid recycling for contaminant removal.

Facile synthesis of oxygen-deficient BiOBrxCl1−x solid solutions for efficient photocatalytic degradation of organic pollutants

In this study, a series of oxygen-deficient BiOBrxCl1−x (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1) solid solution photocatalysts by the microwave hydrothermal method. By changing the Br/Cl molar ratio, the light absorption edge of BiOBrxCl1−x was effectively red-shifted from 345 to 430 nm. The performance of BiOBr0.3Cl0.7 solid solution catalyst showed the best photocatalytic duty for the degradation of norfloxacin (NOR) and methyl orange (MO). The degradation rate of NOR reached 90.2% within 50 min (catalyst dosage: 20 mg), whereas that of MO reached 82.7% within 30 min (catalyst dosage: 5 mg). Environmental factors affecting the degradation of NOR by BiOBr0.3Cl0.7 (such as pH, type of inorganic anions, amount of catalyst, and concentration of NOR) were discussed in detail. The presence of oxygen vacancies (OVs) was confirmed by electron spin resonance (ESR) experiments. Furthermore, free radical capture and ESR experiments identified the main active free radicals involved in the degradation of NOR over BiOBr0.3Cl0.7. Finally, a possible photocatalytic degradation mechanism was proposed.

Design and construction of a novel immobilized Z-scheme-Type II-heterojunction ZnO/ZnCo2O4–Co3O4|Co photocatalyst composite film for efficient norfloxacin degradation with simultaneous hydrogen evolution

The Z-scheme-Type II-heterojunction ZnO/ZnCo2O4–Co3O4 photocatalyst composite film (PCF) was prepared on the cobalt foil by using spin-coating and incomplete solid-state chemical reaction method, which solves the problems that the powder photocatalyst is difficult to recover and reuse and realizes the separation of CO2 and H2. In PCF, ZnO and ZnCo2O4 form a Z-scheme photocatalytic system and ZnCo2O4 and Co3O4 constitute a Type II-heterojunction photocatalytic system. The used cobalt foil acts as both a carrier of photocatalyst and a cathode. The structures and properties of PCF were studied by XRD, SEM, TEM, EDX, XPS, PL, TPR and EIS. Through photocatalytic norfloxacin degradation and hydrogen evolution, the effects of cobalt foil thickness, the coating Zn(OH)2 precipitation layer number, calcination temperature and calcination time on the photocatalytic performance of the Z-scheme-Type II-heterojunction ZnO/ZnCo2O4–Co3O4|Co PCFs were investigated. When the cobalt foil thickness is 0.10 mm, coating Zn(OH)2 precipitation layer number is 2, composite film is calcined under 500 °C for 3.0 h and norfloxacin concentration is 10 mg/L and 50 mg/L, norfloxacin degradation ratio and H2 evolution amount reach 80.70 % and 357.12 μmol/dm2, respectively. In addition, a possible mechanism of norfloxacin degradation with simultaneous H2 evolution caused by immobilized Z-scheme-Type II-heterojunction ZnO/ZnCo2O4–Co3O4|Co PCF was proposed. It is hoped that the work has certain guiding significance to design an immobilized PCF for organic pollutants degradation with synchronous large-scale hydrogen evolution.

Degradation of norfloxacin by red mud-based prussian blue activating H2O2: A strategy for treating waste with waste

The massive accumulation of red mud (RM) and the abuse of antibiotics pose a threat to environment safety and human health. In this study, we synthesized RM-based Prussian blue (RM-PB) by acid solution-coprecipitation method to activate H2O2 to degrade norfloxacin, which reached about 90% degradation efficiency at pH 5 within 60 min and maintained excellent catalytic performance over a wide pH range (3−11). Due to better dispersion and unique pore properties, RM-PB exposed more active sites, thus the RM-PB/H2O2 system produced more reactive oxygen species. As a result, the removal rate of norfloxacin by RM-PB/H2O2 system was 8.58 times and 2.62 times of that by RM/H2O2 system and PB/H2O2 system, respectively. The reactive oxygen species (ROS) produced in the degradation process included ·OH, ·O2- and 1O2, with 1O2 playing a dominant role. The formation and transformation of these ROS was accompanied by the Fe(III)/Fe(II) cycle, which was conducive for the sustained production of ROS. The RM-PB/H2O2 system maintained a higher degradation efficiency after five cycles, and the material exhibited strong stability, with a low iron leaching concentration. Further research showed the degradation process was less affected by Cl-, SO42-, NO3-, and humic acids, but was inhibited by HCO3- and HPO42-. In addition, we also proposed the possible degradation pathway of norfloxacin. This work is expected to improve the resource utilization rate of RM and achieve treating waste with waste.

Enhanced peroxymonosulfate activation by highly magnetic FeCo-CoFe2O4 biphasic fibers for norfloxacin degradation

Transition metal-based non-homogeneous materials have excellent activation properties for persulfates (peroxymonosulfate and peroxydisulfate, abbreviated as PMS and PDS). In this study, FeCo-CoFe2O4 (FC-CFO) biphasic fibers were prepared using the electrospinning technique and a stepwise heat-treatment. The prepared fibers possessed magnetic separation properties (Ms = 91.7 emu/g) and achieved a 93.8 % degradation efficiency of norfloxacin (NFX) in 10 min. Quenching experiment, ESR spectrum, and intermediate product revealed that radical •SO4− and non-radical 1O2 species made major contribution to the FC-CF-500/PMS/NFX system. XPS spectrum and ESR spectrum of oxygen vacancy suggested the abundant oxygen vacancies generated in FC-CFO-500 fibers which could trigger the generation of 1O2. Those findings may demonstrate a reference preparation method of electrospinning nanofibers with an improved PMS activation ability.